Germ cells are set aside from other lineages early in development, later differentiating into functioning gametes. To understand the nature and differentiation of germ cells would be a major achievement in biology, providing important insights into infertility, contraception, human congenital diseases, germ cell tumors, and preservation of endangered species. The molecular basis of germ cell differentiation is beginning to be understood, due to major intellectual and technical advances. General mechanisms of germ cell fate and behavior are emerging from studies in both vertebrates and invertebrates. This meeting, to be held October 10 -13, 2002, 2004 and 2006, will provide a public forum for discussion of all aspects of germ cell research, from the primordial germ cell to the functioning gamete, in diverse model organisms. We expect to attract about 250 participants from all over the world. There are no competing meetings that are so wide in scope. Seven topics have been chosen for platform presentations: Germ Cell Origins, The Embryonic Germ Line, Germ Line Stem Cells, Germ Line/Soma Interactions and Sex Determination, Spermatogenesis, Oogenesis, and Gamete Success and Evolution. Each session will be organized and co-chaired by two experts in the topic, who will invite half the speakers and select the other half from submitted abstracts. We will encourage platform presentations from young scientists. The meeting will facilitate interactions between scientists who study different model systems and different aspects of germ cell biology.